This invention relates to a method for operating and maintaining a clock of a system in a electric exchanger for managing the clock of the system.
In conventional systems, clock management function was executed by reading out a clock of a hardware and determining it as a reference clock, comparing the clock of the hardware on operation and an internal clock of the system, providing only a message without redetermining the clock of the system when there was any difference after comparison, and maintaining continuously only with internal real time clock (RTC) so long as an operator did not alter the clock of the system.